/*
 *  Copyright 2008 Michael Brackx
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 */

package com.googlecode.triples.test;

import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityManager;
import javax.persistence.Persistence;

public class Database {

	protected EntityManager entityManager;
	protected EntityManagerFactory entityManagerFactory;
	private final String persistenceUnitName;

	public Database(String persistenceUnitName) {
		this.persistenceUnitName = persistenceUnitName;
	}

	public void start() {
		entityManagerFactory = Persistence.createEntityManagerFactory(persistenceUnitName);
		entityManager = entityManagerFactory.createEntityManager();
	}

	public void execute(DatabaseAction action) throws Exception {
		entityManager.getTransaction().begin();
		try {
			action.execute(entityManager);
			entityManager.getTransaction().commit();
		} finally {
			if (entityManager.getTransaction().isActive()) {
				entityManager.getTransaction().rollback();
			}
		}
	}

	public void stop() {
		if (entityManager != null) {
			entityManager.close();
		}
		if (entityManagerFactory != null) {
			entityManagerFactory.close();
		}
	}

	// getters

	public EntityManager getEntityManager() {
		return entityManager;
	}

	public EntityManagerFactory getEntityManagerFactory() {
		return entityManagerFactory;
	}

	public String getPersistenceUnitName() {
		return persistenceUnitName;
	}
}
